离心式喷嘴结构参数的多目标优化设计

Multi-Objective Optimization Design of Pressure Swirl Nozzle Geometric Parameters

为提高某型号航空燃油离心式喷嘴的综合雾化性能,对喷嘴的结构参数进行优化设计。基于流体体积(VOF)模型,模拟了喷嘴的内外流场,并通过试验验证了仿真模型的可靠性。为节省多次试验和数值模拟的成本,基于响应面法(RSM)建立了以喷嘴扩张段长度、等直段直径、等直段长度、收缩半角、扩张半角为设计变量,雾化锥角和质量流率为响应变量的代理计算模型。基于得到的表达式,分析了设计变量对响应变量的贡献度和交互影响作用,结果表明:扩张半角对雾化锥角的贡献最大,呈正相关;质量流率受等直段直径的影响最为显著,随着等直段直径的增加而增加,但随着收缩半角的增大而减小。以雾化锥角和质量流率为优化目标,采用NSGA-Ⅱ算法进行多目标优化,优化结果表明:优化后的结构参数使得离心式喷嘴的雾化锥角和质量流率分别提高了8.3%和32.4%。

In order to improve the comprehensive atomization performance ofa pressure swirl nozzle,the geometric parameters ofthe nozzle are optimized.Volume offluid(VOF)model was used to simulate the flow field of the nozzle,and the reliability of the simulation model was verified by experiments.In order to save the cost of tests and simulation,a surrogate model was established based on the response surface method(RSM),taking the nozzle expansion section length,straight line section diameter,straight line section length,convergent semi-angle and divergent semi-angle as the design variables,and spray cone angle and mass flow rate as the dependent variables.Based on the expressions,the contribution and interaction effect of independent variables on response variables are analyzed.The results show that the divergent semi-angle has the greatest contribution and positive correlation to the spray cone angle.The massflow rate is most significantly affected by the straight section diameter,which increases with the straight section diameter,but decreases with the increase ofthe convergent semi-angle.The multi-objective optimization was carried out by using NSGA-II algorithm to optimize the spray cone angle and massflow rate.The results showed that the optimized geometric parameters improve the atomization spray cone angle and massflow rate of the pressure swirl nozzle by 8.3%and 32.4%respectively.